1. Field of the Invention
This invention relates generally to packaging equipment and packaging products and more particularly is directed towards a new and improved apparatus for making and applying to a disposable drinking cup a lid of heat sealable film material from a roll of such material. This invention also relates to an improved disposable drinking cup and lid combination in which the lid is in the form of a film of thermoplastic material heat-sealed to the cup rim.
2. Description of the Prior Art
In our U.S. Pat. No. 4,078,360 and in our co-pending application Ser. No. 966,876, filed Dec. 6, 1978, now U.S. Pat. No. 4,226,072 there is disclosed an apparatus for lidding a disposable drinking cup with a film of thermoplastic sheet material. The apparatus includes a cup support adapted to raise a cup placed thereon into contact with the leading section of a thermoplastic film held by reciprocating gripping jaws. Mounted above the film along the axis of movement of the cup holder is a heated sealing head which comes down against the top of the film to press the film and seal it to the rim of the cup. Upon completion of this sealing operation, the cup drops down, the head moves up and the jaws retract to grip and draw out a fresh section of film in preparation for the next lidding operation. The apparatus is controlled by means of a pneumatic circuit provided with logic modules and control switches in a cooperative arrangement.
It is an object of the present invention to provide improvements in cup lidding apparatus of the sort disclosed in our prior patent and co-pending application. It is a more specific object of this invention to provide an improved sealed container comprised of a cup and lid which is substantially leakproof and is especially adapted for use with hot liquid contents. A further object of this invention is to provide a new and improved heat-sealing head adapted to seal a section of film against the cup lid in an improved manner so as to substantially eliminate any leakage, especially where the cup contains a hot liquid.